In comparison to conventional ovens, counter-top electric ovens or cookers typically offer the advantage of being less bulky and having quicker cooking times. These counter-top cookers or ovens include a power head having a heating unit that is used to heat the cooking enclosure. To reduce the cooking time, counter-top electric ovens typically will rely on a hot air stream that is cycloned around the food by a high speed fan associated with the electric heating element, or by utilizing an infrared heating element in combination with a relatively low speed fan that generates sufficient air circulation in the oven to ensure a relatively uniform temperature distribution in the oven.
Typically, the power head is configured to be seated in the top opening of an oven housing and locked into place by engaging projections or tabs on the rim of the oven housing with corresponding grooves or slots on the power head. In this manner, the power head and the oven housing can be lifted off the base of the oven together as a unit for access to the inside of the cooking enclosure. Locking the power head and the oven housing together also prevents the power head from being lifted off the oven housing during cooking by the pressure built-up inside the cooking enclosure.
Very often the oven housing is made of heat resistant, transparent plastic or glass to enable the user to maintain visual progress of food item being cooked. As a result, known oven housings tend to expand with the temperature increase in the cooking enclosure, causing the locking mechanisms to disengage. Consequently, there is a risk that the power head will become detached from the oven housing during the cooking operation from the pressure inside the cooking enclosure. The oven housing could also slip off the power head as the user lifts the power head to gain access to the inside of the cooking enclosure.